Koser, K.: Migration and Climate Change, 2012

Download PDF Document



The impact of climate change on migration has attracted considerable attention in recent years, among academics, but also in media coverage and on the political agenda. Although there is a striking lack of scientific consensus on what these effects will be, and how many people will be affected, there has been a tendency to pose migration resulting from the effects of climate change as a serious threat, especially in Europe. In the spirit of promoting objective debate and evidence-based policy, this short article attempts to summarize the existing research. It starts by explaining that the link between climate change and migration is by no means straightforward. It then focuses on some of the key questions: how many people will be affected, where will they come from, and where will they go? The final section summarizes the current debate concerning policy responses.

A complex relationship

The relationship between climate change and migration is by no means straightforward – and an important conclusion from the existing research is that climate change does not necessarily result in migration or displacement. Climate change itself does not lead to migration, but some of its effects may - including environmental degradation, sea-level rise, the increasing frequency of certain natural disasters, health impacts, or growing food insecurity.

Different effects have different implications: a distinction is usually made between rapid onset effects such as typhoons and tsunami, and slow onset events including desertification or sea-level rise. While migration is often unavoidable in response to a tsunami, it is usually short-term as it should be possible to return home once the event recedes. In contrast, when migration takes place in response to sea-level rise, for example, it is more likely to be permanent, where land has become uninhabitable as a result of increasing salinization or even submersion. Different policy responses are required for these different scenarios – in one case temporary refuge and a focus on return and reintegration, contrasting with permanent resettlement in the other.

Another set of intervening variables relate to migration being only one of a number of outcomes in response to the effects of climate change. Many people may stay put and accept environmental changes, with the implication that their living standards may decline. Others might remain and adapt in a more active way, for example by building defenses, changing agricultural practices, or adopting new livelihoods. In this context migration is just one of a range of strategies, and may even be the least significant, apart from in particular circumstances such as where low-lying islands submerge, resulting in no alternative but to leave. The choice that people make between these strategies is likely to depend on factors such as their access to resources, their resilience and vulnerability, and their previous experience of migration. The policy implication is that development assistance in general, and in particular for climate change adaptation in affected areas, may be one way to reduce the necessity of migration; although it is worth reiterating that in some situations migration will be inevitable.

Even where migration does result from the effects of climate change, it is important to recognize the range of potential migration responses. Migration may be in reaction to environmental change, or may be proactive in response to the prospect of lasting changes. In the latter case migration can be viewed not as a consequence of climate change, but as a way to adapt to climate change. It follows that supporting migration is one way to promote adaptation to climate change. Migration can involve individual family members or entire families or communities. It can be temporary or permanent; local or long-distance. What is more, migration as a result of the effects of climate change is likely to exacerbate existing flows for example from rural to urban areas, making these different migrants difficult to distinguish. A related issue is that rural-urban migration may actually be moving people into zones of greater vulnerability, for example where they settle in cities in low-lying coastal areas.

Except in unusual cases such as where an entire territory is submerged, it will always be difficult to discern environmental from other motivations to migrate. Most migrants move for mixed motivations that may include environmental impulses, but usually combined with economic, political, and social factors. This is significant in terms of the legal status that may be ascribed to such migrants. Where they are fleeing conflict that may have been exacerbated (or even caused) by the effects of climate change, they would probably qualify as refugees. Where they are moving for economic reasons, even if these have been heightened by the effects of climate change - for example, where growing seasons are shortened-, they would likely be described as economic migrants. In contrast and as expanded below, there exist no legal categories or associated legal or normative frameworks pertaining to migrants who do move primarily as a result of the effects of climate change.

How many?

There is no consensus on the number of people who already have been displaced as a result of the effects of climate change. The Internal Displacement Monitoring Centre (IDMC) estimates that in 2011 over 10 million people were displaced inside their countries as a result of natural disasters because of climate change events (based on 128 recorded natural disasters in 61 countries). At the same time IDMC accepts that its data in this area can only be approximate. It is not always easy to discern migration resulting from natural disasters and that driven by economic and other motivations. Most of the displacement reported is in countries without the capacity to collect accurate data. While climate change may be responsible for certain natural disasters - for example flooding or their increasing frequency -, other natural disasters such as earthquakes have nothing to do with climate change. And as an illustration of the complexity of categorizing displacement, IDMC counts the displacement resulting from the partial meltdown of the Fukushima Daiichi nuclear power plant in Japan as resulting from a technological hazard, rather than the natural disaster that created the hazard.

It is hardly surprising then that forecasting the number of climate change-related migrants in the future is little more than guesswork. In 2005 the UN Environment Programme (UNEP) predicted that 50 millions would be displaced by 2010 – but this prediction was never followed up with any data collection. Different sources have variously predicted that 50 million, 200 million, or 250 million people will be displaced from their homes by 2050 as a result of the effects of climate change. The sources for these estimates are all reputable; all the estimates concern very significant numbers of people; but the differences between them only serve to undermine the credibility of any of them.

Given the lack of consensus over estimates of the number likely to be affected and over what time horizon, focusing on numbers is increasingly viewed as counter-productive. The science of climate change is not robust enough to predict climate change events. Data on contemporary migration (especially internal migration) are too inaccurate to use as a basis for forecasting. The production of data on climate change and migration has become politicized: a criticism that has been leveled at climate change activists is that the potential for migration has been used to leverage attention to their cause, and that many of the estimates put out show little understanding of the complexity of the migration process. Estimates on migration resulting from the effects of climate change can be used to alarm rather than inform. In a recent speech the UN High Commissioner for Refugees argued that rather than debating numbers, the focus should be on the rights of those who have been and may be affected, and how to promote these rights.

Where from?

A combination of environmental vulnerability and economic and political capacity predicts which parts of the world are more likely to be affected by migration resulting from the effects of climate change. Environmental pressures to move will be most extreme in the global mega-deltas, such as the Ganges, Yangtze and Mekong deltas, where flooding is likely to become more extreme and regular; in low-lying islands and coastal areas, such as in the Pacific and on the eastern seaboard of Africa respectively, which may be partially submerged by relatively small sea-level rises; and in water-scarce regions such as the Middle East where drought and rising average temperatures may disrupt agriculture. At the same time, migration is more likely from those affected areas that are also prone to conflict which may compound the pressure to move, where poverty restricts the ability to adapt to climate change, and where poor governance limits the capacity of states to support affected populations in situ.

There is a particular debate about so-called ‘climate change wars’, which may in turn prompt the movement of refugees. Much has been written about conflict over access to increasingly scarce natural resources; the possibility of ‘water wars’ especially between states that share a river system; about scarce food becoming a domestic weapon in civil wars; and about territorial claims to maritime boundaries and offshore resources. Many of these scenarios are highly speculative. There is very little evidence that climate change is influencing conflict; in fact it has been suggested that climate change may promote regional cooperation for example over limited water resources that are shared between states. At the very least, such scenarios underestimate the multi-causality of conflict. The effects of climate change may exacerbate food, water, and energy insecurity in certain parts of the world, or competition over resources; and these may in turn stoke existing tensions or conflicts between rival communities. This is what has taken place in Darfur, which has inaccurately been described by some commentators as the ‘first modern climate-change conflict’. In fact climate has not been the only or even the primary cause. It seems unlikely that the effects of climate change will generate new conflicts; and even if it does there is by no means a causal relationship between conflict and refugee movements.

Where to?

Perhaps the most politicized aspect of the debate about the relationship between climate change and migration concerns where those affected will go. There has been a public concern in many industrialized countries that climate change will result in mass migrations from the less developed world – and these concerns have been stoked by a lack of sound data, political manipulation, and irresponsible media coverage. In fact most migration experts agree that the lion’s share of these movements will be internal, especially from rural to urban areas. A smaller proportion is expected to be cross-border but within the region. And probably only a minority of people compelled to move as a result of the effects of climate change will undertake long journeys from poorer to richer countries. Where they do they are expected to follow established migration networks, for example between former colonies and colonial powers, or trading partners. Nevertheless, even a small proportion of a total of 250 million is still a substantial number of people in absolute terms.

Policy responses

There are three main strands to developing a comprehensive policy approach to climate change and migration. One is mitigation, to reduce the scale of climate change. A second is to support adaptation (including internal displacement) in affected areas. And the third is to manage migration (either as a form of adaptation to or as a consequence of the effects of climate change).

A particular challenge is that at present migrants who cross international borders as a result of the effects of climate change would not be entitled to refugee status according to either the 1951 UN Convention relating to the Status of Refugees or its 1967 Protocol or subsequent regional amendments. This means that the widely-used terms ‘environmental refugee’ and ‘climate change refugee’ are misnomers and legally inaccurate. Some people advocate for an updating of the 1951 Convention to apply to the 21st Century realities of forced migration; but this is widely viewed as unlikely. Obstacles include: resistance from the UN High Commissioner for Refugees (UNHCR) which is the guardian of the 1951 Convention, and its governing member states; the length of time it takes to negotiate international conventions in the field of human rights; and the reality that many states would refuse to ratify a new Convention. The risk of opening up the 1951 Convention is that it would be negotiated downwards to a more restrictive instrument, rather than upwards and outwards. These legal and political obstacles are compounded by a lack of clear empirical evidence on the numbers of people expected to be displaced across borders by the effects of climate change, the time horizon involved, and the extent to which this is likely to be a regional or truly global issue.

Instead international attention has turned to promoting national and regional laws and policies to respond to this new category of displacement. A few states in the industrialized world provide limited humanitarian protection to people from countries affected by natural disasters and climate change. In the USA, Temporary Protected Status (TPS) was introduced as part of the 1990 Immigration Act to provide at least limited protection to people who may not fit the 1951 Convention criteria for refugee status, but cannot be returned to their countries because of insecurity there. Between 1995 and 1999 the status was extended to people from Montserrat following volcanic eruptions there, and more recently to Haitians following the 2010 earthquake. Some analysts have suggested that the European Union Temporary Protection Directive of 2001 may be interpreted to apply to mass influxes of people from natural disasters. Within the EU, Sweden and Finland have both amended their asylum and human rights laws to incorporate some element of ‘environmental migration’. The 2005 Swedish Aliens Act provides for the possibility to provide subsidiary protection on environmental grounds; while the Finnish Aliens Act of 2004 explicitly acknowledges that unusual environmental circumstances can produce mass influxes of migrants who require temporary protection.

But none of these rare examples of national policies and legislation is comprehensive. An important proviso in the USA is that TPS can only apply to people already resident in the USA at the time of the natural disaster, and not to people fleeing the event. Invoking the EU Temporary Protection Directive would require agreement by a majority of Member States which most commentators deem unlikely; and the focus of the Directive on ‘mass influxes’ would probably not cover most migrants from climate change effects who will actually arrive in Europe, as they are likely to be moving over a period of time because of slow onset climate events such as desertification in the Middle East and North Africa. Neither of the relevant provisions in Sweden or Finland has ever been tested, and there are reservations about how they would function in practice – for example it is unclear whether the protection envisaged is temporary or permanent.


There is no need to panic. The effects of climate change will not necessarily result in migration, and where it does migration may be short term and local. Europe is unlikely to be flooded by ‘climate change refugees’ as is often suggested by politicians and in the media. Still there are serious challenges that do need to be confronted, especially concerning filling the protection gaps into which some of those who move as a result of the effects of migration may fall. Effective policy in this field depends on more research and better evidence; an objective debate that informs rather than alarms; and the ability to learn lessons from other states that are beginning to prepare for the challenges ahead.

Selected References

Asian Development Bank (ADB) (2012) Addressing Climate Change and Migration in the Asia and Pacific: Final Report, Manila: ADB

Camillo Boano, Roger Zetter, Tim Morris (2008) ‘Environmentally Displaced People’, Forced Migration Policy Briefing 1, Oxford: Refugee Studies Centre

Stephen Castles (2011) ‘Concluding remarks on the climate change-migration nexus’ in Etienne Piguet, Antoine Pecoud, Paul de Guchteniere (eds) Migration and Climate Change, Cambridge: Cambridge University Press, pp.415-27

Foresight (2011) Migration and Global Environmental Change: Future Challenges and Opportunities, London: Government Office for Science

Paul Herman Jr and Gregory F Treverton (2009) ‘The Political Consequences of Climate Change’, Survival, 51:2, 137-48

Walter Kaelin and Nina Schrepfer (2012) Protecting People Crossing Borders in the Context of Climate Change: Normative Gaps and Possible Approaches, Legal and Protection Policy Research Series, Geneva: UNHCR

Jeffrey Mazo (2009) ‘Darfur : The First Modern Climate-Change Conflict’, Adelphi Series 49:409, 73.74

Jane McAdam (2011) Climate Change, Forced Migration, and International Law, Oxford: Oxford University Press

Norman Myers (2002) ‘Environmental Refugees: A Growing Phenomenon of the 21st Century’, Philosophical Transactions of the Royal Society B, 357:1420, 609-13

Will Somerville (2011) Environmental Migration, Washington DC: Migration Policy Institute

Dr. Khalid Koser, Academic Dean, Geneva Centre for Security Policy, 2012